The dissertation is concerned with the effects of oil spills on the environment, using the 2010 Gulf of Mexico event, which motivated the selection of this research topic, as a case study. It examines the spill from both a social and biological assessment in which policy, technology, and economics direct oil spill response and remediation.
The dissertation is partly based on material collected during two years of fieldwork in Southern Louisiana. The Deepwater Horizon case study includes qualitative research grounded in a participatory action research (PAR) approach. The PAR strategy includes collective inquiry and experimentation through direct experience.
Although historically the effort to mitigate the effects of the Deepwater Horizon spill was the greatest cleanup response to an oil spill, the effort only affected 24% of the oil released in the Gulf. The fate of the remaining oil is unknown. Natural gas was not included in the spill discharge metric, nor will recovered oil (skimming and siphoning) be deducted from the fine that will be assessed on the responsible party, British Petroleum. Response strategies, such as the use of chemical dispersants and in-situ burning, did not remove oil, but instead contributed to the cumulative pollution in the environment. This case study revealed an opportunity to create legislation that motivates increased investment in technologies and response strategies that support the removal of the oil from the environment.
Trough the Deepwater Horizon case study, I also explored alternative spill response technologies and approaches to remediation and restoration. More than a dozen alternative technologies were evaluated and adopted during the 87-day oil spill event. The technologies evaluated included advancements for oil removal -- skimming and shoreline cleanup. Furthermore, for the first time, an oiled marsh was set aside for the purpose of conducting applied oil remediation and restoration research. Through a multi-institutional collaboration, we designed and implemented a restoration project on set-aside marsh in Louisiana. This project abandoned the use of cultivars and instead embraced genetically diverse, locally adapted plants for shoreline restoration. Included in the marsh project was a plant propagation innovation which utilized composted bagasse, a waste product of the Louisiana sugar cane industry, as a growth medium. The bagasse adds valuable organic material to the oil-impacted marsh and proved to be a viable propagation medium for smooth cordgrass (Spartina alterniflora) plants.
Additional soil remediation research, funded by the Chevron Corporation, investigated the use of vermiremediation for crude oil-impacted soils. Analysis of vermitea, the liquid extract from vermicompost, indicated the presence of biosurfactant producing hydrocarbonoclastic bacteria, allowing for the increased solubility of hydrophobic compounds adsorbed to soil. Additional research and field-scale experiments are required to optimize vermiremediation and demonstrate the potential for scaling and adoption.
My research supports the use of natural attenuation of oil-contaminated soil though the adoption of strategies which help to maintain the existing ecosystem. My research findings elucidate the critical limitations of current conventional oil spill response technologies and reveal the environmental tradeoffs that occur during response decision-making. The dissertation demonstrates the need for additional investment in technology innovation and for broader response strategies and preparation for future oil spills.
